Process of smelting refractory ores and producing low-carbon ferro alloys.



No. 865,609. 7 P ATE NTED SEPT. 10, 1907'; ,B. F. PRICE. PROCESS OF SMELT ING REFRACTORY ORES AND PRODUGINGLOWCARBON FERRO ALLOYS. 7 APPLICATION FILED 11017.14. 1905. I

' I 2 SHBVBTS-SHEE T 1.

No. 865,609. PATENTED SEPT.10, 1907. B. F. PRICE. PROCESS OF SMELTING REFRACTORY ORBS AND PRODUCING LOW CARBON FERRO ALLOYS.

APPLICATION FILED NOV.14, 1905.

2 SHEETS-SHEET 2.

To all whom it may-concern:- 1

' operation comprising two stages. 'In the first stage EDGAR' F. PR-ICE, or NiAeARA 'F'A Ls NEW ORK.

rnocnss 0F mn'rme REFRACTORY Y Specification oflletters Patent.

v(mas Am) .PRoD'Uome, Low-cannon rnrmo I ALLOYS. 1

- Patented Sept. 10, 1907.

Application and shims 14,1905. Serial No. 287,356.

Be-it knownlthatl, EDGAR 1?. PRICE; a citizen of the United States, residing atNiagara Falls, in the county of Niagara and State of"New Yoi-k have ii vented certain new and useful Improvements in Processes of Smelting Refractory Ores'and-Producing Low- Carbon Ferro Alloys, ofwhich'theiollowingis a speci fication. A Q

This process is designed for the production of lowcarbon ferrochromium,.ferron anganese, ferrotitanium I ferr'ovanadium and similar-alloys, and contemplates,

the use of ferrosilicon as a reducing agent. It is pos;

sible toelectrically produce this silicid with a silicon content of fifty percent and upwards and very iowin.

carbon.

According to the present invention the production M of lowscarbonferro-alloys-is effected by a continuous ore or iron,an'd carbon. The molten silicid is tapped ferrosilicon high in silicon and low in carbon is produced by electrically smelting a charge of silica, iron from the smelting furnace and allowed to solidify.

The ingot is then broken into fragments which are A mixed with a granular body of the compound to be reduced, for example chromite, and the mixture is.

smelted preferably ina furnace in which the charge serves as a resistance-conductor. A basic flux, such as lime,1 is preferably, mixed with the charge to convert the silica produced by thefreduction of oxid ores into'a fusible slag.

Suitable apparatus for carrying out the process is shown in the accompanying drawings, in which- Figure 1 is an axial section of the furnace for produce ingethe ferrosilicon; "and 2 is an axialsection of and a hearth 3 of carbon, surrounded by a metal casing 4 having an electric terminal 5. The carbon hearth the resistance-furnace for effect reduction. r r p 1 The smelting-furnace shown in Fig.1 comprises sides 2 of refractory electrically-non-conductive material, such as carborundum, siloxicon or silica, or oi carbon,

constitutes one electrode and the other electrode is a depending: carbon rod 6. Tap-holes )7, 8 extend through the side walls at different heights. In using this furnace to carry out the first stage of the process} an arc is established between the-depending electrode and the carbon hearth, and the'charg'e -for example a,

mixture 'of finely ground silica; i'ron ore and cok'e,' the silica and carbon preferably relativelylargei amount-is fed-into the furnace .i'- As geduction 'pro any slag is withdrawn'through the taph ole 7.

. -and the alloy is intermittently tapped'into a casting.

pot 9, fresh charge-materials beingadded as required.

In'the second stage of the process, -the cast ingot f utilizing the ferrosilicon to r hearth," which' is maintained in a pasty or solid condimixture is preferably heated by the resistance-furnace I ferrosilicon isbroken into pieces and the fragments are v mixed with the ore to be reduced and a ux. ,The

shown in Fig. 2. This furnace hasa body 10 of refrac tory non-conductive material-for example chromite or magnesia-surrounded by awater-j'acket 11 The body is supported upon a horizontal metal plate 12, preferably of cast-steel, having a chamber 13 for the circulation of water, and an electric terminal 1 11 Supported upon the body 11 but insulated therefrom by a layer 15 of refractory non-conductive material, is T the upper electrode 16, a downwardly-converging'water-jackete'd iron ring having a terminal '17, the inner surface of the ring beingbare, to contact with the charge. Supported upon the ring-electrodeis an iron dome 18 which carries a bell-and hopper charging mechanism 19 and-has an outlet flue 2 0 for wastej gases. Tap-holes 20, 21 for the slag and alloy extend through the side walls,v at different heights. In em= ployingthis furnace .to carry-out the second stage of the :process, a mixture ofthe'o re to be reduced, for

example chromite, ferrosilicon and-lime, is -fed into 'thefurnace'untiLit substantially fills the stack, the "upper portion of the charge lyingFin contact with the ring-electrode 18. It the charge. 'is normally apoor .conductor,' initial.cfirrentrpaths between the. elec- 8Q trodesare provided. The conductivity of the charge may be increased by using a mixture containing large I pieces of coke orferrosilicon, which lie in contactwith each otherat various, points and thereby-afford direct.

current-paths.' -An electric current ii thenfpassed I betwenjhe electrodesandthrough the charge; serizing.as a resistance conduotor. The charge is thereby.

heated, the temperature gradually risingfltowardthe hearth. by reason of the decreasing cross-section and increasing current and "energydensity, to, a point wherereduction is (affected. The reduced iron and.

chromiumiorm a molten alloy; which accumulates abody in the lower ,part of the'stackflhis body being molten except. for a layer 22 in proximity to the tion" by are, circulated through the chamber 13 of the hearth; Dining the normal operation of thefur nac'eg'thisbody 22 serves as the lower e alectrode,',the-

hearth 12 acting as a terminal..' The slag andalloy'. are

tapped out from time to time and more of the chargemixtureisfed continuous.

This processenables arena-gird containin'gl'a mum or predetermined low percentage ofcarbon continuously producedat irelativelyilow cost, the use of a chargecco'ntaining a relatiyely large amount' of silica-and carbon producing a silicid low in carbon--.

into't he furnace, the process'thus being and serving as. an effectivereducing agent. \lLhiJei't" is preferred .to employ the charge 'as a resistance-con 4 ductor, it is obvious that the 'heat necessary for the :final reductionmay be supplied by passing an electric current through a separate resistor. I L

5' I claim:

1. The process of producing ferrochromiuni, which consists in smelting a charge containing ,ferrosiliconhnd a compound of chromium by means, of an electrically-heated resistance-conductor, as set forth. t

' 2. Theprocess'of producing ferrochromium, which consists in smelting a charge containing ferrosilicon; an o xi-- J :an oxidized compound of a metal reducible by silicon and "alloyable with iron, and a basic flux, bypassinga-n electric '25 current through the charge, acting as a resistance conductor, and thereby heating the charge to the temperature requisite for-reductionyas set forth. i I t 5. The process of producing io'w-carbon ferro-ailoys, which consists in smelting a charge containing ferrosilicon and a compound of a metal reducible by silicon and alloy:

able with iron,'by.passing an electric current through the charge,,acting as a resistance-conductor, thereby heating e the charge to the temperature requisite for reduction, with drawingthe slag and ferro-alloy from the furnace, and supplyingthe charge-mixture as required,'as setforth.

' 6. The process ofproducing low-carbon ferro-alioys,

which consists in smelting a charge containing ferrosiiicon an oxidised compound of a metal reducible by silicon and alloyabie with iron, and a basic flux, by passing an electric. 40 current through the charge, acting as a resistance 'conductor, thereby he'ating -the charge to the temperature req u'isite for-reduction,w ithdrawingthe slag and ferroa iloy from the furnace, and supplying the charge-mixture asrequired, as set forth. 7. The process of producing .loW-carbon ferroalloys, ,which consists in smelting a charge containing ferrosilicon and a compound of a metal reducible by silicon and alloyable with iron, by passing an-electric current through the charge, acting as a resistance-conductor, thereby heating the charge to'the temperature requisite for reduction,.withdrawing thesi'ag and ferro-aiioy from the furnace at differcut levels, and supplying the chargemixture as required, as set forth. I 7

8;The "process of producing low-carbon ferro-ailoys,

which consists in smelting a charge containing ferrosiiicon, an oxidized compound of a metal reducible by silicon and alloyabie with iron, and a basic flux,-by passing an electric current ithrough the charge; acting as a resistance conductor, thereby heating the charge to the temperature requisite for reduction, withdrawing the slag and ferro- :aiioy from the furnace at 'diiferent lev'els, and supplying ti crharg'e-mlxtureas required, as set forth. 9. r'liie process of producing'ferrochromium, which consists in smelting a charge, containing ferrosilicon and a compound of chromium by passing an electric current sistance conductor, and thereby heating the charge to the temperature requisite for reduction, as set forth.

- 11. The process of producing fer'rochromium, which consists in smelting a charge containing ferrosilicon and a compound of chromium by passing an electric current through the charge, acting as a resistance conductor, there by heating the charge to the temperature requisite for reduction, withdrawing the slag and ferro-alloy from the furnace, and supplying the charge-mixture as required, as set forth.

12. The process of producing ferrochromium, which con- .sists in smelting a charge containing ferrosiiicon, an oxidized compound of chromium, and a basic flux, by passing an electric current through the charge, acting as a resistance conductor, thereby'heating the charge to .the tempera .ture requisite for reduction, withdrawing the slag and ferro-ailoy from the furnace, and supplying the chargemixture as required, asset forth.

13. The process of producing ferrochromium, which consists in smelting a charge containing ferrosilicon and :1 compound of chromium by passing an electric current through the charge, acting as a resistance conductor, thereby heating the charge to the temperature'requisitc for reduction, withdrawing the slag and ferro aiioy from the furnace at different levels, and supplying the charge-mixture as required, as set forth. ,1

14. The process of producing ferrochromium, which'con' sists in smelting a charge containing ferros ilicon, an oxiidized compound of chromium, and a basic flux, by passing an electric current through the charge, acting as a re' sistance conductor, thereby heating the charge to the temperature requisite for reduction, withdrawing the slag and ferroaiioy from the furnace at different levels, and supplying 'the charge-mixture as required, as set forth.

15. The process of producing low-carbon ferro-alloys, which consists in smelting a charge containing ferrosiiicon and a compound of a metal reducible by siliconand alloy- -able with iromby passing an electric current through the charge, acting as a resistance-conductor, and increasing the current or energy density through the charge to a point where reduction is eifected,'as set forth.

16. The process ofproducing ferrochromium, which consists in smelting a charge containing ferrosilicon, and a compound of chromium, by passing an electric current through the charge, acting as a resistance conductor, and increasing the current or energy density through the charge to a point where reduction is efiected, as set forth.

I 17. The process of producing ferrochromium, which consists in smelting a charge containing ferrosilicon, an oxidized compound of chromium, and a 'basic flux, by passing an electric current through the charge, acting as a resistance-conductor, and increasing the current or energy density through the charge to a point where reduction is effected, as set forth.

In testimony whereof, I afiix my signature in presence of two witnesses. a EDGAR F. PRICE.

Witnesses:

G. E. Cox, K

- D. Bunoass. 

